Emulsion polymerization with trisubstituted hydroperoxy methanes



United States Patent i EMULSION POLYMERIZATION WITH TRISUBSTI- TUTED HYDROPEROXY METHANES William B. Reynolds and John E. Wicklatz, Bartlesville, Okla, and Thomas J. Kennedy, Borger, Tex., assignors to Phillips Petroleum Company, a corporation of Delaware No Drawing. Application May 8, 1953 Serial N0. 354,384

7 Claims. c1. 26084.1)

This invention relates to an improved process for polymerizing unsaturated organic compounds while dispersed in an aqueous emulsion. In one important aspect this invention relates to the use of faster recipes at low polymerization temperatures for effecting production of synthetic rubber by emulsion polymerization of conjugated diolefins. This application 'is a continuation-in-part of our copending application Serial No. 68,73 6, filed December 31, 1948, together with copending applicationsSerial No. 107,638, filed July 29, 1949, now Patent 2,665,269, and Serial No. 133,466, filed December 16, 1949, now Patent 2,638,464.

With the increasing interest in low temperature emulsion polymerization, many variations in recipes and procedure have been developed in the interest-of economy and efiiciency in addition to the attention given to producing polymeric materials having the desired characteristics. Recipes of the redox type, that is, formulations wherein both oxidizing and reducing components are present, have been widely used. Oxidizing components frequently employed include materials of a peroxidic nature, and particularly compounds such as benzoyl peroxide and cumene hydroperoxide. Even though any peroxidic material might be expected to function in the capacity of the oxidant in a redox emulsion polymerization system, this is not necessarily the case since in some instances little, if any, polymerization occurs while in other cases with different peroxides the reaction takes place at a sat- 'isfactory rate. Some peroxides may function fairly satisfactorily at higher temperatures but are of little value when it is desired to carry out polymerizations at low temperatures, say below the freezing point of water.

We have now discovered that excellent conversion rates can be obtained in emulsion polymerization systems through the use of initiator, or catalyst, compositions comprising a trisubstituted hydroperoxymethane having at least ten carbon atoms per molecule. Not only are rapid polymerization rates obtained at low polymerization temperatures with these compositions, but with some recipes it is also possible to obtain these advantageous results without having present in the polymerization system any "salt of a heavy metal, such as iron. In many instances it is quite desirable to produce a polymeric product completely free from such heavy metals, because of adverse influences of the metal on the physical and chemical properties of the rubber, but with other recipes it has not been feasible to obtain this desired result. The rapid reaction rates obtainable with the recipes of the present invention permit operation at low reaction temperatures, down to as low as 30 or 40 C., or lower.

The hydroperoxymethanes used in the practice of this invention will contain at least ten carbon atoms per molecule, and usually not more than thirty carbon atoms per molecule. They can be represented by the formula R COOH wherein each R, individually, is one of the group consisting of aliphatic, cycloaliphatic, aromatic, olefinic, and cycloolefinic radicals. Each of these radicals can be completely hydrocarbon in character, and can be 2,908,668 Patented Oct. 13, 1959 ICC of mixed character, such as aralkyl, alkaryl, and the like, and can also have non-hydrocarbon substituents, some of which will have the effect of making them more watersoluble and less oil(hydrocarbon)-soluble; particularly useful non-hydrocarbon substituents include oxygen in the form of hydroxy and ether compounds, sulfur in similar compounds (i.e. mercapto compounds and thioethers), and halogen compounds. Examples of such hydroperoxides include diisopropylbenzene hydroperoxide (dimethyl (isopropylphenyl)hydroperoxymethane), methylethyl ethoxyphenyl hydroperoxymethane, methyldecyl methylphenyl hydroperoxymethane, dimethyldecylhydroperoxymethane, methylchlorophenylphenylhydroperoxymethane, and tertiarybutylisopropylbenzene hydroperoxide (dimethyl(tertiary butylphenyl)hydroperoxymethane). Such hydroperoxides can be easily prepared by simple oxidation, with free oxygen, of the corresponding hydrocarbon or hydrocarbon derivative, i.e. of the parent trisubsttiuted methane. The compound to be oxidized is placed in a reactor, heated to the desired temperature, and oxygen introduced at a controlled rate throughout thereaction period. The mixture is agitated during the reaction which is generally allowed to continue from about one to ten hours. The temperature employed is preferably maintained between 50 and C., although in some instances it might be desirable to operate outside this range, that is, at either: higher or lower temperatures. At the conclusion of the reaction the oxidized mixture may be employed as such, that is, as a solution of the hydroperoxidc composition in the parent compound, or unreacted compound may be stripped and the residual material employed. The major active ingredient in such a composition is the monohydroperoxide, or a mixture of monohydroperoxides. This hydroperoxide group appears to result from introduction of two oxygen atoms between the carbon atom of the trisubstituted methane and the single hydrogen atom attached thereto. Where there is another similar grouping in the molecule, the usual method of'production just outlined appears to produce only the monohydroperoxide even though a dihydroperoxide appears to be structurally possible. Thus, in a simple case, from such an oxidation of diisopropyl benzene the primary product appears to be dimethyl(isopropylphenyl)hydroperoxymethane.

One large group of these hydroperoxymethanes'is that group in which each of the three substituent groups is a hydrocarbon radical. One of the subgroups of these compounds is the alkaryl-dialkyl hydroperoxymethanes, in which the two alkyl groups are relatively short, i.e. have from one to three or four carbon atoms each, including dimethyl(tertiarybutylphenyl)hydroperoxymeth ane, dimethyl(diisophopylphenyl)hydroperoxymethane, dimethyl(isopropylphenyl)hydroperoxymethane, dimethyl (dodecylphenyl)hydroperoxymethane, dimethyl(methylphenyl)hydroperoxymethane, and corresponding methylethyl and diethyl compounds, and the like. Another subgroup includes at least one long alkyl group directly attached to the hydroperoxymethane, such as methyldecyl (methylphenyl) hydroperoxymethane, ethyldecylphenylhydroperoxymethane, and the like. Still another subgroup includes trialkyl compounds, such as dimethyldecylhydroperoxymethane, and the like; aralkyl compounds, such as 1-phenyl-3-methyl-3-hydroperoxybutane, can also be considered to be members of this group. A further subgroup includes alkyldiaryl compounds, such as methyldiphenylhydroperoxyrnethane,

methylphenyltolylhydroperoxymethane, and the like. A further subgroup is the triaryl compounds, such as triphenyl hydroperoxymethane,

' tritolyl hydroperoxymethane, and the like. These materused to effect emulsion polymerizations, but their use also frequently results in a more uniform reaction rate over a given reaction period than do hydroperoxides heretofore used. These advantages are particularly pronounced at polymerization temperatures below C., and down to polymerization temperatures as low as 30 or -4() C., or lower.

Particularly suitable for utilization in emulsion polymerization reactions even at low temperatures are recipes in which the polymerization catalyst composition comprises an oxidant and a reductant and in which the oxidizing component employed is a dimethyl(halophenyl) hydroperoxymethane having the formula wherein X is a halogen other than iodine and x is an integer from 1 to 4, inclusive, such as is formed upon reaction of free oxygen with a dimethyl(halophenyl)methane. When the halogenated compounds disclosed herein are utilized as catalysts, it is not necessary to limit the minimum number of carbon atoms to ten. We have also discovered that these dimethyl(halophenyl) hydroperoxymethanes are superior to dimethylphenylhydroperoxymethane itself as oxidants for use in emulsion polymerization reactions, and with some recipes it is possible to effect satisfactory polymerization without having present in the polymerization system any salt of a heavy metal, such as iron.

The halogen-substituted hydroperoxymethanes which are applicable in this invention can be represented by the formula wherein each R is selected from the group consisting of hydrogen, fluorine, chlorine, and bromine, with at least one halogen atom present in the molecule but with the number of halogen atoms attached to the aromatic ring not greater than four. When two or more halogen substituents are present in the molecule, they can be alike or different.

Specific examples of suitable hydroperoxides of this type are dimethyl(2-chloro-4-bromophenyl)hydroperoxymethane, dimethyl(2,3,4 trifluorophenyl)hydroperoxymethane, dimethyl(bromophenyl)hydroperoxymethane, dimethyl(2,3,4,5 tetrachlorophenyl)hydroperoxymethane, dimethyl(2 fiuoro-3,4 dichlorophenyl)hydroperoxymethane, dimethyl(2 fluoro 3 bromo 4 chloro) hydroperoxymethane, dimethyl(2,3,4,5, tetrafluorophenyl) hydroperoxymethane, and dimethyl 2,3-dibromo- 4,5-dichlorophenyl hydroperoxym ethane.

A still more comprehensive group of halogen substituted hydroperoxymethanes which are applicable according to this invention can be represented by the formula where R and R are alkyl, cycloalkyl or aromatic hydrocarbon radicals containing one to ten carbon atoms, or such hydrocarbon radicals substituted with halogen groups of atomic number 9 to 35, or alkoxy groups containing one to ten carbon atoms, Ar is an aromatic nucleus, specifically, a benzene nucleus or a naphthalene nucleus, each X is selected from the group consisting of halogens of atomic number 9 to 35, alkyl groups having one to ten carbon atoms, alkyl groups substituted with halogens of atomic number 9 to 35, and hydrogen, at least one X being halogen, and the molecule containing 30 carbon atoms or less.

Specific examples of compounds of the above formula which are applicable to the invention are diphenyl(isopropylbromophenyl)hydroperoxymethane, decylmethyl- (isopropyldichlorophenyl) hydroperoxymethane, cyclobutylmethyl (tertiarybutyltrifiuorophenyl) hydroperox methane, methylphenyl 1 (2-bromo-3-cl1loro-6-tertiarybutylnaphthyl)hydroperoxymethane, chlorotolylisopropyl diisopropyldichlorophenyl) hydroperoxymethane, 2-phenylheptylamyl(4 bromotolyl)hydroperoxymethane, heptadecylethyl (butyldichlorophenyl) hydroperoxymethane, methylpropyl (difluorodecylphenyl) hydroperoxymethane, octylcyclohexyl (trichloronaphthyl)hydroperoxide, isopropylpentyl (difluorodichloronaphthyl) hydroperoxymethane, chloropropylhexyl (trichlorophenyl) hydroperoxymethane, chlorocyclohexyloctyl(amylchlorobromonaphthyl)hydroperoxymethane, phenyltolyl(diisopropylfluoronaphthyl)hydroperoxymethane, di(chlorodecyl) bromotolylhydroperoxymethane, 2 methoxyheptyl 5 chloropentyl(2,3 diisopropyl 4,5 difluorophenyl)hydroperoxymethane, 4 hydroxyhexylcyclohexyl 2 (6,7- chloro 4 n butylnaphthyl)hydroperoxymethane, 6- heptoxydecylethyl(2 chloro 5 tertiarybutylphenyl)- hydroperoxymethane, naphthyldodecyl(tetrafluorophenyl)hydroperoxymethane, trichloronaphthylhydroxypropyl(diisopropylchloronaphthyl)hydroperoxymethane, 2,2- dichloroamyl 4 hydroxyphenyl(2,3 di n propyl- 4 chloro 6 fluorophenyl)hydroperoxymethane, phenyl 4, 6 dimethoxyheptyl(isoamyltrichlorophenyl)hydroperoxymethane, 2 chloromethyl 4 methoxyoctylmethyl(dichloronaphthyl)hydroperoxymethane, dichlorocyclohexyl 5 heptoxyhexyl(1,2 dichloro 3 isopropylphenyl)hydroperoxymethane, dimethyl(2 trifiuoromethyl 4-fluorophenyl)hydroperoxymethane, and isopropylpentyl [2 (2,2,5 trichloroheptyl)4 chlorophenyl]hydroperoxymethane.

A still more preferred group of halogen-substituted hydroperoxymethanes which are applicable in this invention are those of the above formula in which R and R are alkyl groups containing one to twelve carbon atoms, one X is a halogen of atomic number 9 to 35, another X is an alkyl group containing one to twelve carbon atoms,

and the remaining Xs are halogens of atomic number 9 to 35, alkyl groups containing one to twelve carbon atoms or hydrogen. Specific examples of the applicable compounds of this group are diethyl(chlorophenyl)hydroperoxymethane, butyl(dichlorophenyl)hydroperoxymethane, octyl isopropylchlorophenyl) hydrop eroxymethane, methyldecyl(isopropylfluorophenyl) hydroperoxymethane, tertiarybutylpropyl(2 chloro 3 bromo 4 methylphenyl)hydroperoxymethane, rnethyl(2,4 diethyl 3- bromophenyl) hydroperoxymethane, diheptyl diisopropyldichlorophenyl)hydroperoxymethane, methylisopropyi- (methyldecylfluorophenyl)hydroperoxymethane, dimethyl(2 bromo 3 fiuoro 4,5 diethylphenyl)hydroperoxymethane, dodecylpropyl(isopropyltribromophenyl)- hydroperoxymethane, methyltertiarybutyl(triisopropylfluorophenyl)hydroperoxymethane, dodecylbutyl 2(4- propyl-6,7-dichloronaphthyl)hydroperoxymethane, chlorodecylmethyl(di tert hexylfiuorophenyl)hydroperoxymethane.

We use the hydroperoxides discussed herein as oxidants in polymerization recipes at low polymerization temperatures, i. e. from about 10 C., or just above the freezing point of water, to well below the freezing point of water, such as -40 C. or lower. The recipe will also include a reductant compound or composition. In some recipes this will be a single compound, or a mixture of homologous compounds, such as hydrazine, ethylenediamine, diethylenetriamine, aminoethylethanolamine, ethylenemethylethylenetriamine, tetraethylenepentamine, and the like. These compounds have the general formula RHN (CHXCHXNH) m (CHXCHX) NHR 5 where each R contains not more than eight carbon atoms and is of the group consistingof' hydrogen, aliphatic cycloaliphatic, aromatic, olefinic, and cycloolefinic radicals, and each X contains 'not more than three carbon atoms and is of the group consisting of hydrogen and aliphatic radicals, in is an integer between and 8, inclusive, and n is an integer of the group'consisting of 0 and 1 and is' 1 when m is greater than 0. Each of the foregoing radicals (other than hydrogen) can becompletely hydrocarbon in.character, and can be of mixed character when containing six or more carbon atoms, such as alkylcycloalkyl, aralkyl, alkaryl groups, and the like, and can also have non-hydrocarbon substituents, some of which will have the effect of making them more watersoluble and less oil(l1ydrocarbon)-soluble; particularly useful non-hydrocarbon substituents include oxygen in the form of hydroxy and ether compounds, sulfur in similar compounds (i.e. mercapto compounds and thioethers) and halogen compounds. In such recipes, such a polyamino compound appears to act as a reductant, and no other activating ingredients, such as compounds of polyvalent-multivalent metals, or reducing ingredients, such as a reducing sugar, need be present in order to obtain satisfactory and rapid polymerization of the monomeric material, even at subfreezing temperatures. The amount of polyamino compound used to obtain optimum'results also is dependent upon other ingredients in the recipe. Preferred results are usually obtained with between 0.02 to 5 parts by weight, per 100 parts of monomeric material, of the polyamino compound. In other recipes a composition is used which comprises one compound which is an oxidation catalyst, or activator, and another different compound which is a reductant. The oxidation catalyst is generally selected from a group of materials consisting of compounds of metals such as iron, manganese, copper, vanadium, cobalt, etc. In general it is assumed that the metal must be a multivalent metal and in such a condition that it can change its valence state reversibly. The other ingredient ordinarily present is a reductant, and is usually an organic material such as a reducing sugar or other easily oxidizable polyhydroxy compound. capacity are glucose, levulose, sorbose, invert sugar, and the like. The multivalent metal ion of the oxidation catalyst can easily and readily pass from a low valence state 'to a higher valence state, and vice versa. Sometimes this compound, when present in its lower valence state, can function in the dual role of reductant and oxidation catalyst. One commonly used oxidation catalyst is an iron pyrophosphate, and is separately made up in aqueous solution from a ferrous salt, such as ferrous sulfate, and a pyrophosphate of an alkali metal, such as sodium or potassium.

When a ferrous pyrophosphate activator is used, it is preferably prepared by admixing a ferrous salt, such as ferrous sulfate, with a pyrophosphate of an alkali metal, such as sodium or potassium, and water and heating this mixture, preferably for the length of time required for maximum activity. A reaction occurs between the salts, as evidenced by the formation of a grayish-green precipitate. When preparing the activator the mixture is generally heated above 50 C., for variable periods depending upon the temperature. For example, if the mixture is boiled, a period of twenty minutes or less is sufficient to produce the desired activity, and the time of boiling may even be as low as 30 seconds. One convenient method of operation involves maintaining the temperature of the activator solution at'about 60 C. for a period of heating ranging from to 30 minutes. Prior to heating the activator mixture the vessel is usually flushed with an inert gas such as nitrogen. In general it is preferred to heat the mixture below the boiling point, say at a temperature around 55 to 75 C.

In cases where the activator is prepared just prior to use, it is generally employed in the form of an aque- Compounds frequently employed in this 6 ous dispersion as described above. However, the solid activator maybe isolated and the crystalline product used, and in' this form it is preferred in some instances. Subsequent to heating the activator mixture, it is cooled to around room temperature and the solid material separated by centrifugation, filtration, or other suitable means, after which it is dried. Drying may be accomplished in vacuo in the presence of a suitable drying agent, such as calcium chloride, and in an inert atmosphere such as nitrogen. When using this crystalline product in emulsion polymerization reactions, it is generally charged to the reactor just prior to introduction of thebutadiene. This crystalline material .is believed to be a sodium ferrous pyrophosphate complex, such as might be exemplified by the formula A a or perhaps Na FeP O In any event the complex, whatever its composition, is only slightly soluble in water and is one active form of ferrous ion and pyrophosphate which can be successfully used in our invention. It may be incorporated in the polymerization mixture as such, or dissolved in sufficient water to produce solution. Other forms of multivalent metal and pyrophosphate may also be used, so long as there is present in the reacting mixture a soluble 'form of a multivalent metal, capable of existing in two valence states and present primarily inthe lower of two valence states, and a pyrophosphate.

The amounts of activator ingredients are usually expressed in terms of the monomers charged. The multivalentmetal should be within the range of 0.10 to 3 millimols per parts by weight of monomers, with v .2 to 2.5 millimols being generally preferred. The amount of pyrophosphate should be within the range of 0.10 to 5.6 millimols based on 100 parts by weight of monomers; however, the narrower range of 0.2 to 2.5 millimols is more frequently preferred. The mol ratio of ferrous salt to alkali metal pyrophosphate can be between 1:0.2'and 123.5, with a preferred ratio between 1:035 and 1:2.8.

In effecting emulsion polymerization of a monomeric material, particularly when a batch-type or semi-batchtype operation is carried out, the reactor is usually first charged with the aqueous medium, which contains the desired emulsifying agent, and the monomeric material is then admixed with agitation of the contents. At the same time a reaction modifier, such as a mercaptan, is also included, usually in solution in at least a part of the monomeric material. An activator solution and an oxidant are separately added to the reaction mixture, and reaction then proceeds. A preferred manner of adding these two constituents is usually to have the activator solution incorporated in the aqueous medium prior to addition'of the monomeric material, and to add the oxidant as the last ingredient. Sometimes, however,

satisfactory polymerization results can be obtained when this procedure is reversed. It is also sometimes the practice to add portions of one or the other of the activator solutions and oxidant intermittently, or continuously, during the course of the reaction. If the operation is carried out continuously, streams of the various ingredients are admixed in somewhat the same order prior to their final introduction into the polymerization reaction zone.

As previously stated, it is usually desirable that the multivalent metal be present in its lower valence state. With some recipes, it is unnecessary to include an organic reducing agent either in the activator solution or in the polymerization mixture. However, particularly at temperatures above 0 C., a faster reaction is some times obtained with some recipes when a small amount of an organic reducing agent, such as a reducing sugar is included in the polymerization recipe, and it is frequently more desirable to incorporate this in the reaction system by first including it in the activator solution along with the other ingredients. When the multivalent ion is present in its higher valence state, it is usually necessary to include in the activator solution an organic reducing agent. As a result the multivalent ion will be partially reduced and a substantial amount of the multivalent ion will be present in its lower valence state when the activator solution is ready for addition to the polymerization mixture.

It is usually preferred that the multivalent ion be iron, and the activator solution may be prepared from any of the readily available soluble iron salts, such as ferrous sulfate, ferric sulfate, ferrous nitrate, and the like. A pyrophosphate of sodium or potassium is also usually used in preparing the activator solution. Apparently the ferrous salt and the pyrophosphate interreact to form some kind of a complex compound.

The monomeric material polymerized to produce polymers by the process of this invention comprises unsaturated organic compounds which generally contain the characteristic structure CH =C and, in most cases, have at least one of the disconnected valencies attached to an electrone gative group, that is, a group which increases the polar character of the molecule such as a chlorine group or an organic group containing a double or triple bond such as vinyl, phenyl, cyano, carboxy or the like. Included in this class of monomers are the conjugated butadienes or 1,3-butadienes such as butadiene (LS-butadiene), 2,3-dimethyl-l,3-butadiene, isoprene, piperylene, 3-furyl-l,3-butadiene, 3-methoxy-1,3- butadiene and the like; haloprenes, such as chloroprene (2 chloro 1,3 butadiene), bromoprene, methylchloroprene (2-chloro-3-methyl-1,3-butadiene), and the like; aryl olefins such as styrene, various alkyl styrenes, p-chlorostyrene, p-methoxystyrene, alpha-methylstyrene, vinylnaphthalene and similar derivatives thereof, and the like; acrylic and substituted acrylic acids and their esters, nitriles, and amides such as acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl alpha-chloro-acrylate, methyl methacrylate, ethyl methacrylate, butyl-methacrylate, methyl ethacrylate, acrylonitrile, methacrylonitrile, methacrylamide, and the like, methyl isopropenyl ketone, methyl vinyl ketone, methyl vinyl ether, vinylethinyl alkyl carbinols, vinyl acetate, vinyl chloride, vinylidene chloride, vinylfurane, vinylcarbazole, vinylacetylene and other unsaturated hydrocarbons, esters, alcohols, acids, ethers, etc., of the types described. Such unsaturated compounds may be polymerized alone, in which case simple linear polymers are formed, or mixtures of two or more of such compounds which are copolymerizable with each other in aqueous emulsion may be polymerized to form linear copolymers.

The process of this invention is particularly effective when the monomeric material polymerized is a polymerizable aliphatic conjugated diolefin or a mixture of such a conjugated diolefin with lesser amounts of one or more other compounds containing an active CH =C group which are copolymerizable therewith such as aryl olefins, acrylic and substituted acrylic acids, esters, nitriles and amides, methyl isopropenyl ketone, vinyl chloride, and similar compounds mentioned hereinabove. In this case the products of the polymerization are high molecular weight linear polymers and copolymers which are rubbery in character and may be called synthetic rubber. Although, as can be readily deduced from the foregoing, there is a host of possible reactants, the most readily and commercially available monomers at present are butadiene itself (1,3-butadiene) and styrene. The invention will, therefore, be more particularly discussed and exemplified with reference to these typical reactants.

With these specific monomers, it is usually preferred 8 to use them together, in relative ratios of butadiene to styrene between 65:35 and :10 by weight.

Alcohols which are applicable, when operating at low temperatures, comprise water-soluble compounds of both the monohydric and polyhydric types, and include methyl alcohol, ethylene glycol, glycerine, erythritol, and the like. The amount of alcoholic ingredient used in a polymerization recipe must be sufiicient to prevent freezing of the aqueous phase and generally ranges from 20 to 80 parts per parts of monomers charged. In most cases the amount of water employed is sufficient to make the total quantity of the alcohol-water mixture equal 180 parts. In cases where it is desired to use a larger quantity of the alcohol-water mixture, say around 250 parts, the amount of alcohol may be increased to as much as parts. It is preferred that the alcohol be such that it is substantially insoluble in the non-aqueous phase, and that 90 percent, or more, of the alcohol present be in the aqueous phase. A high-boiling alcohol such as glycerine is difiicult to recover from the resulting serum; a low-boiling alcohol such as methanol is easily removed and frequently preferred. Other low-boiling alcohols such as ethanol, however, are frequently too soluble in the liquid monomeric material to permit satisfactory operation. If the resulting latex tends to gel at low reaction temperatures, a larger proportion of aqueous phase should be used. It is generally preferred that the emulsion be of an oil in water type, with the ratio of aqueous medium to monomeric material between about 1.521 and about 2.75:1, in parts by weight. In the practice of the invention suitable means will be necessary to establish and maintain an emulsion and to remove reaction heat to maintain a desired reaction temperature. The polymerization may be conducted in batches, semicontinuously, or continuously. The total pressure on the reactants is preferably at least as great as the total vapor pressure of the mixture, so that the initial reactants will be present in liquid phase. Usually 50 to 85 percent of the monomeric material is polymerized.

Emulsifying agents which are applicable in these low temperature polymerizations are materials such as potassium laurate, potassium oleate, and the like, and salts of rosin acids. Particularly useful are the specific mixtures of salts of fatty acids and of rosin acids, which seem to have a synergistic action when used with some of these same hydroperoxides, as more fully disclosed and claimed by Charles F. Fryling and Archie E. Follett in their application Serial No. 72,534, filed January 24, 1949. However, other emulsifying agents, such as non-ionic emulsifying agents, salts of alkyl aromatic sulfonic acids, salts of alkyl sulfates, and the like which will produce favorable results under the conditions of the reaction, can also be used in practicing the invention.

The pH of the aqueous phase may be varied over a rather wide range without producing deleterious effects on the conversion rate or the properties of the polymer. In general the pH may be within the range of 9.0 to 11.8, with the narrower range of 9.5 to 10.5 being most generally preferred.

The mercaptans applicable in this invention are usually alkyl mercaptans, and these may be of primary, secondary, or tertiary configuration, and generally range from C to C compounds, but may have more or fewer carbon atoms per molecule. Mixtures or blends of mercaptans are also frequently considered desirable and in many cases are preferred to the pure compounds. The amount of mercaptan employed will vary, depending upon the particular compound or blend chosen, the operating temperature, the freezing point depressant employed, and the results desired. In general, greater modification is obtained when operating at low temperatures and therefore a smaller amount of mercaptan is added to yield a product of a given Mooney value, than is used at higher temperatures. In the case of tertiary mercaptans, such as tertiary C mercaptans, blends of tertiary 9 C C and C mercaptans, and the like, satisfactory modification is obtained with 0.05 to 0.3 part mercaptan per 100 parts monomers, but smaller or larger amounts may be employed some instances. In fact, amounts as large as 2.0 parts per"100'parts of monomers may be used. Thus the amount ofmer'captan isadjus'ted to suit the case at hand.

Advantages of this'invention are illustrated by the following examples. r eiea'c'ana, and their proportions,

the other specific ingredients ofthe recipes are presented as being typical and should not be construed to limit the invention unduly. One of'the interesting properties of the trisubstituted hydro-peroxy-niethanesi discussed herein is their low solubility in the aqueous phase, their high solubility intheliquid monomer phase,'and the influences of an emulsifying agent on these factors.

The distribution of cumene hydroperoxide and of diisopropylbenzene hydroperoxide between the liquid phases of a typical polymerization recipe, with andwithout soap at l C., was investigated (in the absence of the usual polymerization catalyst activator). .It was first established that less than two hours was required to reach an equilibrium distribution. The peroxides were determined by the method of Wagner et al., Anal. Chem. 19, 976 (1948). The systems employed were the follow- Parts by weight Butadiene 70 Styrene 30 Water 180 Methanol 40 Cumene or diisopropylbenzene hydroperoxide 0.20-0.21 K-laurate (when used) 5.0

Temperature, 10 C.

The liquid mixtures were agitated at 10 C. for two hours and then allowed to stand at -l0 C. until phase separation was adequate. The following data were obtained upon analysis of the hydrocarbon and water phases:

Percent Hydroperoxide In Hydroperoxide, Type Parts Soap HG H2O Phase Phase Oumcne 0. 20 None 83 17 Do 0:20 K-laurate 60 4O Diisopropylbenzene 0121 None 90 10 Do 0. 21 K-laurate 79 2] The solubilization of hydroperoxides by soap is evident; With both hydroperoxides the solubility in the aqueous phase is more than doubled by the presence of soap. The greater solubility of cumene hydroperoxide in the aqueous phase, as compared with the solubility of diisopropylbenzene hydroperoxide, is also indicated by the data.

Additional distribution experiments were conducted at 5 C. in an alcohol-free system. The following results were obtained:

. 0 Example I The copolymerization of butadiene and styrene was carried out at -10 C. using the following recipe:

Dimethyl(isopropylphenyDhydroperoxymethane composition l 0.15 (0.77 millimol). Activator solution-- Potassium chloride 0.4. Ferrous sulfate,

FeSO -7H O 0.2 (0.70 millimol). Sodium pyrophosphate, V

Na P O -10H O 0.32 (0.72 millimol).

. 1 A blend of tertiary C12, C14, and C16 aliphatic 'mercaptans in a ratio of 3 I lparts by weight.

2 Calculation based on percent diisopropylbenzene monohydroperoxide. e

In preparing the dimethyl(isopropylphenyl)hydroperoxymethane (or diisopropylbenzene hydroperoxide) composition, amixture of 200ml. of freshly-distilled m-diisopropylbenzene and 0.5 gm. of the sodium salt of curnene hydroperoxide was charged into a reactor provided with an efficient motor-driven stirrer. After the reactor was charged it was immersed in a constant temperature bath maintained at C. Dry oxygen was then passed ,throughthe reactor and the reaction mixture was agitated vigorously. As the oxidation proceeded small samples were withdrawn periodically from the reactor and analyzed for hydroperoxide content. The oxidation was stopped after two hours when the reaction mixture reached an active oxygen content of 4.0 percent or a 'hydroper'oxide content of 47.5 percent, calculated as the monohydroperoxide of m-diisopropylben'zene. The contents of the reactor were then Withdrawn immediately, chilled to 0 C., placed in a suitable container, and stored at +5 C. i i

The oxidation mixture from this oxidation is made up of unreactedm-diisopropylbenzene, the monohydroperoxide of that hydrocarbon, and other oxygenated products. When thismixture was subjected to distillation at 152 mm. pressure and at room temperature, the volatile, nonhydroperoxidic constituents were removed as distillate. The still-pot residue recovered at the end of the distillation had an active oxygen content of 4.9 percent or a hydropei oxide content of 58.9 percent, calculated as the monohydroperoxide of m-diisopropylbenzene. v

Preparation of the activator'cornposition was effected by dissolving the ferrous sulfate, sodium pyrophosphate, and potassium chloride in the requisite quantity of water and heating the resulting mixture at 60 C. for 40 minutes. Concentrations of ingredients were adjusted in such a way ,that.25 ml. of the activator solution was used per .100 grams of monomers charged;

Polymerization vwascarried out according to the conventional procedure. A conversion of 60 percent was reached-in 6 hours.

Example II The recipe of Example I was followed except that the emulsifier employed was potassium tetrahydroabietate. Two runs were made at l0 C., one using 0.15 part diisopropylbenzene hydroperoxide (0.77 millimol) as the oxidant and the other using 0.12 part cumene hydroperoxide (0.78 millimol). In the run using diisopropylbenzene hydroperoxide ya 60 percent conversion was reached in 7.8 hours while in the run in which cumene hydroperoxide was employed, 12.3 hours was required before a 60 percent conversionwas obtained,

' Example III The following recipe was employed for carrying out a series of butadiene/ styrene copolymerizations:

Parts by weight Butadiene 72.

Styrene 28. Water, total 180. Rosin soap, potassium salt, pH

10 ,(Dresinate 214) 4.7. Mercaptan blend 0.25. Diisopropylbenzene hydroperoxide composition Variable. Potassium hydroxide 0.037. Potassium chloride 0.5. Dextrose 1.0.

Activator solution Potassium pyrophosphate,

K P O 0.165 (0.50 millimol). Ferrous sulfate,

FeSO .7H O 0.14 (0.50 millimol).

Water to make 10 ml. of solution. 1 See Example I.

The activator composition was prepared by heating a mixture of the ferrous sulfate, potassium pyrophosphate, and water at 60 C. for 20 minutes.

The dextrose, potassium hydroxide, and 25 parts water were heated at 70 C. for 25 minutes and added to the soap solution. The remaining ingredients were charged .in the conventional manner. Polymerization was effected at 5 C. The time-conversion data are recorded below together with the amounts of the hydroperoxide employed.

hydroperoxide as the oxidant.

The following receipe was employed:

Parts by weight I Ferrous sulfate, FeSO .7H O 0.08 (0.29 millimol). Potassium pyrophosphate,

K P O 0.101 (0.31 millimol). Dextrose 1.00. Potassium hydroxide 0.03.

1 Santomerse #1.The commercial product was treated with isopropanol and the resulting slurry heated to 74 C. It was then cooled to 16 C. and filtered to remove any inorganic salts present. The product obtained was extracted with pentane to remove the unsulfonated material and then dried.

9 See Example I.

A mixture of 5.0 grams of dextrose and 5.0 ml. of 3 percent potassium hydroxide was made up to 50 ml. with water and digested 11 minutes at 70 C. The requisite quantity of this mixture was then employed in the polymerization recipe.

The activator solution was prepared by dissolving 1.77 gm. potassium pyrophosphate'(K P O-,) in approximately 50 ml. water and adding it to 1.40 gm. ferrous sulfate (FeSO .7H O) dissolved in approximately 50 ml. water. The mixture was made up to 100 ml. and heated 23 minutes at 60 C.

The emulsifier, water, dextrose solution, and activator were charged to the reactor in the order named after which the mercaptan dissolved in styrene was added. The butadiene was then introduced, the temperature adjusted to 5 C., and the hydroperoxide added. Polymerization was effected at 5 C. using the conventional technique. Results obtained after a 13-hour reaction period in runs containing different amounts of diisopro- (135555359 Hydwpemmde converswn' Percent 40 pylbenzene hydroperoxide are shown below together with Run per 01 t M111 1 2 7 12 a control run in which 0.10 part cumene hydroperoxide Fe Par 5 1 5 Hours Hours Hows was substituted for the diisopropylbenzene hydroperoxide.

O. 375 0. 037 O. 19 13. 0 15 l6 Conversion 0.75 0-0 4 558 87 Hydroperoxide Parts Millimol Percent, 1. 0 0. 098 0.50 4.1 43. 8 83.5 13 Hours 1. 5 0. 147 0. 75 3. 1 32. 5 74 2. 0 0. gag 1. 0 2.1 23. 5 6% 3.0 0. 9 1.5 15 .10 0. 51 2.7 1 1. 3 0.1 0. 66 9. 0 35. 5 64. 5 8 5 ,1 0. 02 0. 87.2 0. 7.

1 Run 7 was made with 0.1 part cumene hydropcroxide (100 percent) 1 0 0, gas substituted for the diisopropylbcnzene hydroperoxide composition.

Example IV Example VI The recipe of Example I was followed except that the emulsifying agent employed was the potassium salt of hydrogenated tallow acid. Specifications for this soap are as follows:

Iodine No. 52 maximum Iodine No. minus thiocyanogen No. Not to exceed 6 Saturated acid below C 1.0% maximum Unsaturated acid above C 2.0% maximum Saturated acid above C 5.0% maximum Two runs were made at 10 C., .the first one using 0.15 part diisopropylbenzene hydroperoxide (0.77 millimol) and the second employing 0.12 part cumene hydroperoxide (0.78 millimol). In the first run a percent conversion was reached in 4.6 hours while in the second case a 12-hour reaction period was required to reach the same conversion.

Example V A series of butadiene-styrene copolymerizations was carried out using variable amounts of diisopropylbenzene Two polymerization runs were carried out at 5 C. using the receipe and procedure of Example V except that variable amounts of ferrous sulfate, potassium pyrophosphate, and hydroperoxide were used. A control run was also made in which cumene hydroperoxide was employed as the oxidant. The data are herewith presented.

Example VII A series of polymerization runs was carried out at 5 C. using the two hydroperoxides, cumene and diisopropylbenzene, as oxidants and potassium soaps of .va'rious commercially available organic acids as emulsifying agents. The following recipe was employed.

Parts of weight 1 See Example I.

Potassium soaps were prepared from the following commewially available materials. r

' '(1) Neojat D--242.A hydrogenated oleic acid-rosin acid mixture.

Butadiene 70. 5 Styrene 30. Water 170.

.Emulsifier 5.

Mercaptan blend 1 0.25. 'Hydroperoxide (See below.) Activator 10.

'FeSOUH O 0.14 (0.50 millimol). K P o 0.165 0.50 millimol).

(2) Neofat S-142.-Refined hydrogenated tall oil containing a high percentage of rosin acid.

(3) lndusoiL A mixture containing 55-60 percent fatty acids, 34-38 percent rosin acids, and 640% sterols, higher alcohols, etc.

The superiority of diisopr'opylbenzene hydroperoxide in 11 cases is clearly demonstrated, and is shownto bevery make in S e Example VIII given in Example III. In three runs the amount of the hydroperoxide was varied from 0.088 to 0.177 part (0.37 to 0.75 millimol) per 100 parts monomers. The amounts of the otheringredients were held constant.- A control run using 0.1 part (0.66 millimol) cumene hydroperoxide was also made. The following tabulation shows the results obtained.

' Conversion, Per- FeSOflHzO, Mols Percent Parts Hydroperoxide Parts Millimols oxli delMol 2-hr. 7-hr. 12-hr.

0.14 Triisopropylbenzene 0.088 0.37 0. 75 3.2 34.4 68.6 0.14.. .do. 0.118 0.50 1.0 4.6 41.0 76.4 0.14.. .do 0.177 0.75 1.5 13.5 66.8 90.5 0.14 Oumene 0.10 0.66 1.3 10.7 32.8 65.8

Acid Employed for Preparation Hydroperoxide g ofKSoap Mme 83it8fi. ??it? 3:1

Nemtsm m {ui.iRYTPfEiif?::::: a; stabelitem {ISLZSIESSSRYTPFEZ?I":: 35:3 Resin-731 acid --l8t?5323?f3tifz 22:3 we {8ti8P-E ?jititi.... 2:3

Example IX The recipe of Example III was followed for carrying out a series of polymerization runs except that tent-butyL isopropylbenzene hydroperoxide 'Was used as theoxidan t. ,The preparation of tert-butylisopropylbenzene hydroperoxide was effected by the oxidation of tert-butylism propylbenzene at 125 C. using as an initiator 0.46 part of the potassium salt of diisopropylbenzene hydroperoxide per 100 parts of the hydrocarbon to be oxidized. The reaction was allowed to proceed 5 hours at which time the concentration of hydroperoxide in the mixture was 16.05 percent. Polymerization was effected at 5 C. using the same procedure as that given in Example III. In four runs the amount of the hydroperoxide was varied from 0.078 to 0.208 part while the quantities of the other ingradients were held constant. A control run using 0.1 par-t cumene hydroperoxide was also made. The following tabulation shows the results obtained:

Conversion Per- FeSOflHgO, Mols Percent Parts Hydroperoxide Parts Millimol oxide/M01 Fe-H 2-hr. 4.5-111'. 7hr.

0.14 Tert-butylisopropylben- 'zene -5--- 0. 078 0. 37 0. 17. 4 39. 3 52. 0 0.14 d 0 0. 104 0. 50 1. 0 22.1 47. 0 71. 8 0.14"- do 0. 156 0. 75 1. 5 18. 0 38. 8 61. 7 0.14- do 0. 208 1.00 2.0 18. 3 40. 0 64. 6 0.14 Cumene 0. 10 0. 66 1.3 9. 5 22. 1 37. 8

15 Example X The recipe of Example III was followed for carrying out a series of polymerization runs except that dodecylisopropylbenzene hydroperoxide was used as the oxidant.

1 6 amount of hydroperoxide was varied from 0.062 to 0.250

part while the quantities of the other ingredients were held constant. A control run using 0.1 part cumene This hydroperoxide was prepared by the Oxidation of 5 hydroperoxide was also made. The followlng tabulation decylisopropylbenzene which had been previously prepared shows the results obtained:

FBSO4.7H1O Hydroperoxide Mol Ratio Conversion, Percent Hydroperoxide to Fe Parts Millimols Type Parts Millimols 2-hr. fi-hr. 7-hr.

0.14 0.50 -meth lisopro yl benp zene. 0.062 0.37 0.75 11.8 39.0 52.0 0.14 0.50 0.083 0. 50 1.0 5.2 23.2 38.7 0.14 0.50 do. 0.166 1.00 2 6.7 25.2 41.2 0.14 0.50 p-methylisopropylbenzene. 0. 250 1. 50 3 0 3.6 17.0 42.3 0.14 0.50 Cumene 0.10 0.66 1 3 7.8 24. 5 36.0

by the alkylation of isopropylbenzene with l-dodecene. V

5 C. using the same procedure as that given in Example III. In four runs the amount of the hydroperoxide was varied from 0.12 to 0.32 part while the quantities of the other ingredients were held constant. was also made. The following tabulation shows the re- A control run Example XII Meta-methylisopropylbenzene hydroperoxide (dimethyl- (Z-methylphenyl)-hydroperoxymethane) was prepared by the oxidation of methylisopropylbenzene containing to percent of the meta compound, 25 to 30 percent of the para compound and 4 to 7 percent of the ortho compound. Since the meta-compound predominates, the oxidation product is so designated. Oxidation was efiected at 126 C. using as an initiator 0.9 part of the potassium salt of diisopropylbenzene hydroperoxide per 100 parts of the hydrocarbon to be treated. The reaction was allowed to proceed 8.75 hours at which time the concentration of hydroperoxide in the reaction mixture was 14.1

sults obtained: percent.

Conversion, Percent FGSO4-7H20, Hydroperoxide Parts Millimols Mols Per- Parts oxide/M01 Fe- 2-111. 4.5-hr. 7-11r.

0.14 Dodecylisopropylben- Example XI The recipe of Example III was followed for carrying Para-methylisopropylbenzene hydroperoxide was prepared by the oxidation of p-methylisopropylbenzene at a temperature of 126 C. using as an initiator one part of the potassium salt of diisopropylbenzene hydroperoxide per parts of the hydrocarbon to be oxidized. The reaction was allowed to proceed for 5.5 hours at which time the concentration of hydroperoxide in the reaction mixture was 14.1 percent.

The recipe of Example III was followed for carrying FeS 04.71110 Hydroperoxide M01 Ratio, Conversion, Percent Hydroperoxide to Parts Millimols Type Parts Millimols Fe++ 2-hr. fi-hr. 7-hr.

O. 14 0. 50 n1 -rnethylisopropylbenzene 0. 062 0.37 0. 75 10. 2 29. 8 48.0

out a series of polymerization runs except that p-methyldure as that given in Example III.

Example Xlll Dodecyltoluene hydroperoxide (methyl-decyl-(methylphenyl)-hydroperoxy-methane) was prepared by the oxidation of dodecyltoluene which had been previously pre- In four runs the 75 pared by the alkylation of toluene with l-dodecene. Oxieeoemes m 7 dation was effected at 140 (X -using as an initiator 0.5 A mixture of the emulsitying'agent, water, and pop ofthe ota siu t. o q se ropy z ueh mda 4 tass' h dro de pq pe q p q i y g i m fig tassium chlon e was prepare 11 p rum y x1 1 faction. w s cbntiim M w at A added toad ust the pH to 10.3; A SOllltlOlI'Of the hydrothe concentrationof the hydroperoxideiu'tliereactldii 51 peroxide and mercaptan in styrene was then introduced mixture was 7.5 percent. V

v D t The reclpe of Example Hiwast foflotwed for Hg 7 followed by the butadiehne The reactor was pressured 0 out aseriesofpolymerization runsexccpt jthat dotlecyl per Square mch gauge Wlth mtrogen and the toluene hydf p gxl jt a I temperature adjusted to C. Sufficient water was added nieriza'tiori was e ected at'-5 C. using thesameprocedure v I asfhat given in, Example KE fiuggg tolhetetraethylenepentamine to make a solutlon f h di-biji-xidg w jjgd f o 2 1 m 11 part this m1xture was then charged to the reactor. Polymer1- Whlle the quamltls P the; 01 n ed nt were held Zatio'n .was effected in the conventional manner while the constant. A eontrol run using 0.1 pa'rt cumeiie hydro h M at C A H 1 a1 peroxide was also made. The data"a're herewith pre empera'ure was 6 con 0 run was so sented. made using cumene hydroperoxide as the oxidant. Re-

FeSO .7HaO Hydroperoxlde 7 Mg}. gratlo, Conversion, Percent peroxide Parts Mlllimols Type Parts Mtllimols To Fe 1 2-hr. 5-111. 7-l1r.

0. 14 0 dodecyltoluene 0. 11 0. 37 0. 5. 9 25. 0 37. 4 0.14 0.50' 0.22 0.75, 1.5 13.0 47.2 p 67.8 0.14 0.50 0.365 1 .25 2.5 1226 45.0 71.2 0.14 0. 50 0.511 1.75 3; 5 L 0. 6 18.8 1 34.4 0.14 0.50 0:10" 0.66 1.3 7.8 24.5 36.0

Example'X'I'V sults from the various runs are tabulated below.

In several of the foregoingexarnples; comparisons were 30' i 1 V V A made between various concentrations of some specific gg g g trisubstituted hydroperoxyn ethanes having ten .or more 1 1 Oxlda'nt carbon atoms per molecule and one fixed concentration of cumene hydroperoxide. This particular [concentration is one of the most favorable, as is shown by the follow- 35 hours hours ing data. The recipe of Example III was used, at 5C. Diisopropylllgenzene lilyddroperoxifiixnn ,43 0 1 l Trlisopropy enzene y roperox 0-. 66 Wlth "X ampunts of cum i x d P Tert'butylisopropylbenzene hydroperoxide 66 of the dnsopropylbenzene hydropero xlde composltlon of Dodecylisopropylbenzene hyd1'0peroxide- 25 98 that example. These runs were made ara'difie'renr time; l f ml hyrdmpetoxlde (control) 33 92 which accounts for the slight differences in results. 46

Curnene' Hydro: 7 Conversion, percent peroxide M01 Ratio, 1 1 1 1 Hydroper- 1 oxide to Parts Millimols Fe Z'HIS' 513m: THT'ST I2Hrs 24 Hrs.

0.03s 0. 251 .5 11.5 2511s 42. q 62.4 71.4 0:057 0:375 .75 11:2 f 29.2, 40. 00.0 89.0 0. 076 0. 50 '1'10' 9T9 27. 8 40. 7 69.9 93. 6 0.10 0.66 1.3 9:8' 25:3- '38.

1 See Example I. p 7

It is interesting.tonotethafi in this speeifiefr cipe; there Example XVI iS little variation COnVe I'Sl OH the =relat1ve afiiolifil? A series of polymerizations was carfidout 3f 0f Cumefie hydfopefoxideovf n; 1 12 c -5B1 using different emulsifiers in the following tert-butylisocontrast, not y (10651136 othef-hydrpfdiflqfi' pfopyllienz'enehydroperoxide-tetraethylenepentarninerecgive faster rates, but the rates show a more defined varrai r; I I 1 tion with the relative amount of hydroperoxider,.. o 3 1 Parfs 5 weight Example XV Z8- A series of'runs e m e 'i 'u ishd i imn h d Water, iQ-IIIIIIIIIL 19'2. peroxides were employed as oxidants in the following 1, q polymerization recipe: 351 p 4 i i Q I 7 Parts by W g 5.0. Butadienepcue" 1 ene hy- 1 01472 2.27 minimise); 0.27srs- 1111111 1018 'drope'r6xide'..

'lfi Tetr-aethyl'enepeiitamine seeljlxampleIf.

A mixture of the emulsifying agent, water,' n1etha'rio1,

1 See Ex'a'mple i. 1 a 11 a """ll' this mixture a solution of the hydroper'oxide and'mercap and potassium chloride was prepared and potassium hy- 1 droxide added to adjust the pH to the desired level. To- 1 Example XVIII The hydroperoxide to tetraethylenepentainine ratio was.

varied in aseries of polymerization runs made at -10 C.

using therecipe of Example XVII. The following re-- suits were obtained:

; TertbutylisopropyI- Tetraethylenepenta- Conversion, Percent ibenzene Hydroperoxide mine Mol Ratio, 1 Hydroperoxide/ I amine 3 Parts 1 Mi'flimols Parts Millimols 4 hrs. 7 hrs. 24 hrs.

was then ad usted to C. Suffictent water was Example XIX added to the tetraethylenepentamine to make a solution and this mixture was then charged to the reactor. merization was carried out in the conventional manner with the temperature being held at l0 C. The results are herewith presented:

A series of polymerization runs was made at l0 C. V

to study the effect of varying the pH in the following recipe:

Parts by weight Butadiene 70.

Styrene 30. Water 192.

Methanol 48. Rosin soap 3.5. Fatty acid soap 1 1.5. Mercaptan blend 2 0.25. Tert-butylisopropylbenzene hydroperoxide 0.416 (2 millimols). Tetraethylenepentamine 1.50. Potassium chloride 0.25. Potassium hydroxide Variable.

1 Dresinate 214/K-SF flakes. 2 See Example I..

The pH, the quantity of 1.04 N potassium hydroxide added, and the time-conversion data are shown below. A control run was made using cumene hydroperoxide in place of tert-butylisopropylbenzene hydroperoxide and these data are also presented.

M1 1.04 N KOH/IOO g. monomers 4.0 7.

hrs. hr

pH of Soap Solution 24.0 hrs.

eaaaeaaa 1 Oumene hydroperoxide.

Poly- Conversion, percent Several ethylene amino compounds were employed as activators in the following polymerization recipe:

Parts by weight Butadiene 70. Styrene 30.

Water" 180. Soap flakes 1 5.0. Potassium chloride 0.4. Mercaptanblend 0.1.

- Tert-butylisopropylbenzene hydroperoxide 0.416 (2.0 millimols). Activating compound (4.0 millimols) :K-SF: flakes. I 7 See Example v The procedure of Example XV was followed with the temperature of polymerization being held at 5 C. The following results were obtained: 40.

Conversion, Percent Amino Compound 3.5Hrs. 7Hrs. 24Hrs.

I Ethylorwdiaminn 5 7 60 Diethylenetriamine. 15 28 76 .Tetlflethylonopnnmminn 80 Triethylenetetramine 48 73 96 5 Example XX A polymerization run was made using the recipe of Example XIX, except that,sec-propylenediamine (1,2-diaminopropane) was employed as the. activator. The following time-conversion data were obtained:

50 Time, hours! Conversion, percent 7 Example XXI jAminoethylethanolamine was used as the activator in.

thegpolymerization recipe of Example. XIX. A conversion of percent was reached in 24 hours.

Example XXII -Therecipe of Example XIX was employed when carrying out a polymerization reaction at 5 C. using hydrazine, added as hydrazine hydrate, as the activator. A

576 conversion of 16 percent was reached in 24 hours.

"21 Example XXI-II i series; of .polym'eriiationf. was carried? out at 10 C. using the following recipez' See Example I.

In all runs the niillinol ratio of hydroperoxide to amine was 0.5 :1 but the initiator level was varied. The following results were obtained:

Conversion, 1

Hydro- Millimol Percent Time to 60% peroxide, Amine, Level Conversion; Parts I Parts Hydro- 1 Hours peroxide 4.0 6.5 24.0

Hrs. Hrs. Hrs.

Example XXIV V V The following recipe was employed for carrying out the copolymerizationof butadiene with styrene at 5 C. Parts by weight Butadiene a.. 70 Styrene Y 30 Water Fatty acid soap A 0.5 Sodium alkyltoluene sulfonate 1.0 Rosin soap, potassium salt 1.5 Sodiurrr salt of condensed alkyl aryl sulfonic acid e 0.25 Mercaptan blend 4 0.4 Diisopropylbenzene hydroperoxide (100%) 0.15 Potassium chloride 0.5 Potassium hydroxide 1 0.05 Activator composition FeSO -7H O 0.14 K P O 0.177 Dextrose 1.0 Booster solution:

Water 5 Potassium chloride 0.1 Potassium hydroxide 0.06

1 Potassium Oflice Rubber Reserve soap.

Dresinate 214.

1 See Example I. For the preparation of the activator composition, the

dextrose "and potassium pyrophosphate were first dissolved in parts'watei' and=the mixture then heated-'to' 9599 C. and held at this temperature for 10 minutes. The solution was cooled to 60 C1, the solid ferroussullate added, and the mixture cooled to room temperature beforebeing'chargedto'the reactor; 7 t

The emulsifiers, Daxad-ll', potassium hydroxide, and

potassium chloride, together with 65 parts water, were charged-to the reactor. The pH of this charge was 11.3'.

The mercapta'n dissolved in the styrene was then intro-' duced followed by the butadiene. After cooling this mixture to 5 C.', the activatorcompositiori was added and finally the hydroperoxide.

After polymerization'had 1'22 continued for seven hours, the booster solution contain ing water, potassium chloride, and potassium hydroxide was added; A 54.7 percent solids latex was obtained in 36.4 hours and the latex was fluid. At this point the conversion reached was 96.2 percent.

Example XXV The copolymerization of but-adienewithstyrene was elfec'tedat 5 C. accordin'g'ito mereuowtngreupe:

' Parts by weight As in Example XXIV.

The same charging procedure as 'that given in the preceding example was employed, all ingredients being introduced initially. A 52 percent solids latex was obtained in 27 hours.

7 Example XXVI A high solids latex was: prepared at 5 C. using the following polymerization recipe:

' Pans byweight Butadiene 70 Styrene 30 Water '70 Soap flakes 1 2.5 Mercaptan blend 1 0.30 T ert-butylisopropylbenzene hydroperoxid'e 0.188' Daxad-ll 1 0.50 Potassium chloride 0.80 Potassifirii'hydroxide .1... "0.05 Activator compositid'ri FeSO -7H 'O 0.21 K P O 0.266

1 As in Example X XiV. The activatorcomposition was prepared as follows:

the ferrous sulfate was dissolved i n- 61 parts water and 1 the potassium pyrophosphate added. The mixture was diluted with 4 parts water, heated to Q, and cooledto room temperature before being used. A A g t The charging procedure given in Example was employed with all ingredients being added initially. A latex containing 53 percentsolidswas obtained in 25.5 hours.

An additional run was'made in which the activator level was reduced to 0.5 millimol (0.14 part FeSO -7H' 0' and 0.177 part K P 0 A latex containing 54.2 P6115; cent solids was obtained in a reaction period of 32.6

hours.

- Example- XX VII- The following recipe was employed for'the production of a high solids latexat 5 Butadiene Styrene 30 Water s Soap flakes 1 2.5 Daxad-11 1 0.5 Mercaptan blend 0.3 Potassium chloride 0.8 Ro a i m, hydro ide Tertbutylisopropylbenzene hydroperoxide 0.208 Tetraethylene entaniine 0.378

1 As in Example XXIV.

Parts by weight} t 70 hydroperoxide, and finally the activator composition.

Booster Solutions Ifolymerization was effected at C. The time-conver- Added sion data are recorded below, together with the amounts of hydroperoxide employed. For purposes of comparigt? 5 son, a control run was made using cumene hydroperoxide in an amount previously found to be optimum for this recipe. W t 2. r t;r :1e 0.104 Tg t i lggigggggimgz hydmpemxme"' 0'104 8: (H04 Hydroperoxlde FeSO4'7H2O HAS/isle Conversion, Percent i peroxide] The reactor was purged with nitrogen and the water, Parts Parts M01 Fe zHrs' 511m emulsifier, Daxad-ll, potassium hydroxide, and potas- Slum chloride charged" T miXtlfre f Previously 0.086 0.375 .14 0.5 0.75 30.3 73.4 33.7 heated to 50-60 C. to dlssolve all mgredients and was 0.5 1 0% 7 3 -0 cooled to roomtemperature prior to being charged. The 8: 228 3 3: 8 2 $3; 2: 8:3 pH of this solution was 11.8. The temperature was next 0.1 0. 66 0.14 0.5 1.3 12.5 20.5 42.0 adjusted to 5 C. and a mixture of the amine in three parts water was introduced. A solution of the mercapcumene hydmpemxide (control)- tan in styrene was added followed by the butadiene after Example XXIX which the temperature was adjusted again to 5 C. and Dimethyl(chlorophenyl)methane (100 parts), prepared the hydroperoxide finally introduced. The reactor was by the alkylation of chlorobenzene with propylene, was then pressured to 30 pounds per square inch gauge wlth oxidized by charging it to a reactor together with 1.3 mtrogen. After a reaction time of 42.2 hours, the latex parts of the potassium salt of triisopropylbenzene hydrocontained 44.3 percent solids. At this point the conperoxide, this latter compound being employed as an verslon had reached 75.7 percent. initiator for the reaction. The temperature was adjusted 1 Example XXVI to 140 C. and dry oxygen introduced over a 5-hour period while the mixture was stirred. The concentration Dus9propylchlombenzene (1.00 parts) prepared by of hydroperoxymethane at this point was 11.0 percent by alkylatlon of chlorobenzene with propylene under condiwelght. Portions of this material were used to supply tions such as to add two isopropyl groups to the benzene e resulting dimethyl(chlorophenyl)hydroperoxymethnucleus, was charged to a reactor, together with 1.6 parts ane, 1n the amounts mdicated, as the oxldant 1n the folof the potasslum salt of tert-butylisopropylbenzene hydrolowin o1 merization red peroxide, heated to 130 C., and oxygen introduced at g p y p Parts b Weight a controlled rate for a two-hour period while the mix- Butadien 72 y ture was'agitated. At the conclusion of the reaction the St mm 6 concentration of resulting monohydroperoxide in the rey Water, total 180. action mixture was 17.0 percent. This material was R i O otassium Saltl 47 employed as the oxidant in a series of polymerization ig fi runs at 5 C. using the following recipe: D an Parts by Wei ht D1methyl(chlorophenyl)hydrog peroxymethane Variable. Butadlene 72 h d 0 037 Styrene 28 Potassium y ro x1 e Potassium chloride 0.5. Water, total 180 D v 1 extrose 1.0. Rosm soap K Salt Activator com osition f p blendz -.---Y- 4:5 K4P O P 1. 5 (0 50 minimol) Dnsopropylchlorobenzene hydroperoxide 2 7 (100%) Variable FeSO -7H O 0.14 (0.50 mlllimol).

Potassium hydroxide 0.037 f si s fij f f 513: E is Potasslum chlonde A blend of tertiary C1 C14, and C10 aliphatic mercaptans Dextrose 1.0 50 in a ratio of 3 1 1 parts by weight. Activator composition The activator composition was prepared by heating a K P O- Variable mixture of theferrous sulfate, potassium pyrophosphate, FeSO -7H O Variable and water at 60 C. for 20 minutes. :gH (E emul sifiIer solution (Dresinate 214), 10. The dextrose, potassium hydroxide, and 25 parts water 68 6 were heated at 70 C. for 25 minutes and added to the For the preparation of the activator composition, the soap solution. The mercaptan dissolved in the styrene following proporti ns of ingredients were heated at was then added, the temperature adjusted to the desired C. for 20 minutes: K P O 0.165 gram (0.50 millimo level, the butadiene introduced followed by the hydro- FeSO -7H O, 0.14 gram (0.50 millimol); water to make peroxide, and finally the activator composition. Poly- 25 ml. ofsolution. 60 merization was effected at 5 C. The time-conversion The dextrose, potassium hydroxide, and 25 parts Wadata are recorded below together with the amounts of ter were heated at C. for 25 minutes and added to hydroperoxide employed. For purposes of comparison, the soap solution. The mercaptan dissolved in the stya control run was made using cumene hydroperoxide rene was then added, the temperature adjusted to the (dimethylphenylmethane) in an amount previously desired-level, the .butadiene introduced followed by the 65 found to be optimum for the recipe.

Mols Hy- Conversion, percent Hydroperoxymethane From F0804. 7H30, droper- Parent Compound Parts Millimols Parts oxymethane per 2Hrs. 5Hrs. 7Hrs.

MoiFe Dimethyl(ch1oro hen Dmethane. 0.07 0.375 0.14 0.75 20.8 56.0 77.4 a Do 0.0935 0.50 0.14 1.0 17.3 53.4 75.4 D0 0.14 0. 0.14 1.5 14.3 46.4 68.8 Dimethylphenylmethane 0. l 0. 66 0. 14 1. 3 12. 9 31. 4 49. 3

25 These data show the superiority of dimethy1(chlorophenyl)hydroperoxymethane over dimethylphenylhydro peroxymethane as an oxidant in low temperature emulsion polymerization reactions.

26 taining at least one polymerizable organic monomer containing a CH =C group in aqueous emulsion in the presence of 0.1 to 10 millimols per 100 parts by weight of monomers of an organic hydroperoxide represented Example XXX 5 by the formula Polymerization of a monomeric material comprising X R 1,3-butadiene and styrene was carried out, using the I following recipe and a polymerization temperature of X (E0011 C. 10 X X B1 Parts by weight X Butadiene 70.

Where R and R are alkyl groups containing 1 to 12 Methanol '45 15 ar on atoms and X is selected from the group consisting Potassium rosin soap, pH 122 of hydrogen, halogen of atomic number 9 to 35, and Potassium f tty id Soap alkyl groups of 1 to 12 carbon atoms; at least one X (ORR) 3.5. being alogen and at least one X being alkyl, the total Bl d t n-C C C alkyl 15, number of carbon atoms in the compound not exceeding mercaptans 0.25. 20 30, 0.1 to 3 millimols per 100 parts by Weight of mono- Hydroperoxide Variable (0.5 Inillim0 mers of an inorganic ferrous salt, 0.1 to 5.6 millimols per Tetraethylenepentamine D- 100 parts by weight of monomers of an alkali metal K PO 0- pyrophosphate, the mol ratio of ferrous salt to alkali In one run the hydroperoxide was that obtained from metal PY P P being between 110-2 and and oxidizing dimethyl(chlorophenyl)methane with 7 per- 0.02 to 5 parts by weight per 100 parts of monomers of cent conversion in 4 hours, 12 percent in 6.5 hours, and a reducing sugar.

60 percent in 24 hours. In an accompanying run the 2. Process of claim 1 wherein the organic monomers hYdl'OPBIOXidB used Was Obtained from oxidizing 01111161115, comprise a major amount of 1,3 butadiene and a minor as discussed herein, with 6 percent conversion in 4 hours, amount f styrcnc 12 percent in 6.5 hours, and 45 percent m 24 hours. A process in accordance with claim 1 in which the Example XXXI organic hydroperoxide is dimethyl (t-butylchlorophenyl) hydroperoxymethane.

D1methyl(d1chloropheny1)methane (100 parts), prepared by the alkylation of a mixture of orthoand para- B00658 m f' P Wlth clalm 1 W the dichlorobenzene (principally the ortho compound) with orgamc hydroperoxlde methyldecyl P PY propylene, was oxidized by charging it to a reactor toorophenyl)hyfimperoxymethan? gether with one part of the potassium salt of tert-butyl- ?rocess In accordance Wlth clalm 1 Whereln the isopropylbenzene hydroperoxide, this latter compound be- Orgamc hYdmPemXide is y y y ing employed as an initiator for the reaction. The tem- 4O p y y p r xym thane. perature was adjusted to 130 C. and dry oxygen in- 6. Process in accordance with claim 1 wherein the troduced over a 3.75-hour period while the mixture Was organic hydroperoxide is dimethyl(2-bromo-3-fluoro-4,5- stirred. The concentration of hydroperoxymethane at diethylphenyl)hydroperoxymethane. this point was 14.8 percent by Weight. Portions of this 7 A process Comprising polymerizing a mixture material were used to Supply the YeFuItmg Kf taining at least one polymerizable organic monomer conchlorophenyl)hydroperoxymethane, 1n the amounts mtaming a CH2=C group in aqueous emulsion in the i as the p senes of runs usmg the Poly" presence of 0.1 to 10 millimols per 100 parts by weight merlzatlon recipe given 1n Example I. The procedure of monomers of dimethyl (isopropylchlomphenyl)hyd1 of Example I was followed for the preparation of the eroX methane 01 to 3 millimols er 100 art b activator composition, charging the materials to the rep I p p s y actor, and carrying out the polymerization The time Werg t of monomers of an morgamc ferrous salt, 0.1 conversion data are recorded below together with the to m lu1m1S Per 100 Parts by Welght of {monomers of amounts of hydroperoxymethane employed, F an alkall metal pyrophosphate, the mol ratio of ferrous poses of comparison, a control run was made using di- Salt to alkali metal Pyrophosphate being between 2 methylphenylmethane in an amount previously found and 123.5, and 0.02 to 5 parts by weight per 100 parts Of to be optimum for the recipe. monomers of areducing sugar.

Mols Hy- Conversion, percent Hydroperoxymethane From F0804. 71120, droper- Parent Compound Parts Millimols Parts oxymethane per 2 Hrs. 5 Hrs. 7 Hrs. M01 Fe i f fi ifi ffi f i l l: 0. 084 0.38 0.14 0.75 18.4 53.3 77.1

Do 0.221 1.0 0.14 2.0 20.6 58.8 85.0 Dimethylphenylmethane 0.10 0.66 0.14 1.3 9.8 30.0 42.1

While the invention has been described in connection References Cited in the file of this patent with a present, preferred embodiment thereof, it is to be understood that this description is illustrative only UNITED STATES PATENTS and is not intended to limit the invention. 2,638,464 Reynolds et a1. May 12, 1953 We claim: 2,665,269 Reynolds et a1. Jan. 5, 1954 1. A process comprising polymerizing a mixture con 4 Conner Oct. 4, 1955 

1. A PROCESS COMPRISING POLYMERIZING A MIXTURE CONTAINING AT LEAST ONE POLYMERIZABLE ORGANIC MONOMER CONTAINING A CH2=C< GROUP IN AQUEOUS CMULSION IN THE PRESENCE OF 0.1 TO 10 MILLIMOLS PER 100 PARTS BY WEIGHT OF MONOMERS OF AN ORGANIC HYDROPEROXIDE REPRESENTED BY THE FORMULA 